From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51843) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dQZbI-0004V5-3B for qemu-devel@nongnu.org; Thu, 29 Jun 2017 09:35:21 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dQZbE-0005dL-MV for qemu-devel@nongnu.org; Thu, 29 Jun 2017 09:35:16 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37708) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dQZbE-0005cE-FP for qemu-devel@nongnu.org; Thu, 29 Jun 2017 09:35:12 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 6CE60C0BFBD6 for ; Thu, 29 Jun 2017 13:35:11 +0000 (UTC) Date: Thu, 29 Jun 2017 16:35:04 +0300 From: "Michael S. Tsirkin" Message-ID: <20170629163418-mutt-send-email-mst@kernel.org> References: <1498710417-7807-1-git-send-email-peterx@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1498710417-7807-1-git-send-email-peterx@redhat.com> Subject: Re: [Qemu-devel] [PATCH] intel_iommu: fix migration breakage on mr switch List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Xu Cc: qemu-devel@nongnu.org, Juan Quintela , Jason Wang , Laurent Vivier , "Dr . David Alan Gilbert" On Thu, Jun 29, 2017 at 12:26:57PM +0800, Peter Xu wrote: > Migration is broken after the vfio integration work: > > qemu-kvm: AHCI: Failed to start FIS receive engine: bad FIS receive buffer address > qemu-kvm: Failed to load ich9_ahci:ahci > qemu-kvm: error while loading state for instance 0x0 of device '0000:00:1f.2/ich9_ahci' > qemu-kvm: load of migration failed: Operation not permitted > > The problem is that vfio work introduced dynamic memory region > switching (actually it is also used for future PT mode), and this memory > region layout is not properly delivered to destination when migration > happens. Solution is to rebuild the layout in post_load. > > Bug: https://bugzilla.redhat.com/show_bug.cgi?id=1459906 > Fixes: 558e0024 ("intel_iommu: allow dynamic switch of IOMMU region") > Signed-off-by: Peter Xu > --- > hw/i386/intel_iommu.c | 17 +++++++++++++++++ > 1 file changed, 17 insertions(+) > > diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c > index a9b59bd..36b231d 100644 > --- a/hw/i386/intel_iommu.c > +++ b/hw/i386/intel_iommu.c > @@ -2332,11 +2332,28 @@ static void vtd_iommu_notify_flag_changed(MemoryRegion *iommu, > } > } > > +static int vtd_post_load(void *opaque, int version_id) > +{ > + IntelIOMMUState *iommu = opaque; > + > + /* > + * Since commit 558e00 ("intel_iommu: allow dynamic switch of > + * IOMMU region"), I would drop this part of the comment. It isn't of interest to people reading code directly, while people reading git history see the commit log. > memory regions are dynamically turned on/off > + * depending on context entry configurations from the guest. After > + * migration, we need to make sure the memory regions are still > + * correct. > + */ > + vtd_switch_address_space_all(iommu); > + > + return 0; > +} > + > static const VMStateDescription vtd_vmstate = { > .name = "iommu-intel", > .version_id = 1, > .minimum_version_id = 1, > .priority = MIG_PRI_IOMMU, > + .post_load = vtd_post_load, > .fields = (VMStateField[]) { > VMSTATE_UINT64(root, IntelIOMMUState), > VMSTATE_UINT64(intr_root, IntelIOMMUState), > -- > 2.7.4